Here's a link to patent 4069719. There are additional illustrations in the patent doc.
http://www.google.com/patents?id=8LAwAAAAEBAJ
I often use the Google patent search for ideas for mechanisms. If you find one relevant patent, there are often others cited and you can check them out.
Then there are endless hours of entertainment reading patents such as the MIG welder attachment for a drill that converts it into a spool gun. Or the golf clubs that are powered by a shotgun shell.